California Code, Insurance Code - INS § 662.1

Proof of mailing or delivery of a notice of cancellation to a lienholder or an additional interest on a policy to which this chapter applies shall be sufficient to terminate the interest of the parties provided the notice is mailed or delivered at least the maximum number of days prior to termination of the parties' interest as required by Section 662.  For purposes of this section, “delivery” includes electronic transmittal or facsimile or personal delivery.  No lienholder or additional interest shall require a more restrictive form of notice.